I have a problem venting my dryer away from an A/C condenser unit. The dryer vent on the exterior of the house is about 3 feet from the condenser unit. Obviously, lint is building up around the vent and on the condenser.
The condenser unit is in an alcove of the house and is shielded from view by a solid vinyl fence with the bottom of the fence being about 3” off the ground.
I can extend the exhaust location for the dryer past the condenser and through the fence and install an endcap on the outside of the fence. However, I have the following questions:
1. What type of duct can be installed on the exterior of the house without rust/corrosion issues? I know PVC is not allowed. Galvanized metal will eventually rust. Aluminum duct maybe? Joints will be sealed with aluminum tape. Any additional coatings needed on the aluminum?
2. Unfortunately, the termination point outside the fence will be closer to the condenser unit that the current termination cap. The 6’ run to get through the fence with a slight slope to allow condensation drainage will place the cap about 12” from the ground. With the 3” gap under the fence, is this an issue? If so, I can add a 3” wide piece of treated wood on top of an existing treated wood landscape edging to close the 3” gap. The length of the treated wood scab would extend at least 5’ past the vent cap. Are there any code or other issues with the idea?
3. The installation will consist of a a 3' run of interior 4" vent, 1-90 degree ell (4") and 6' of 4" vent pipe on the exterior with an end cap termination. The total equivalent pipe run accounting for the ell would come out to 14' or 15', will under the 25' limit.